Chromecast has become a new platform. On Monday, Google opened up the dongle to outside developers with the release of a software development kit (SDK) and an open API, raising the possibility of a new type of Google TV for business users and consumers.

Attached to a HDMI port on a HD TV or display, the $35 USB stick-sized Chromecast, originally launched in July, allows a user to stream online content from a laptop, phone or tablet. With the availability of the SDK and an open API, third-party developers can now build Chromecast support into their apps or Web sites. In other words, Google may now have launched a new kind of Google TV, so that business users can display output from more kinds of apps for business meetings and consumers can view and interact with new kinds of content on a TV.

In a posting on the Google Chrome Blog, Chromecast Product Manager and Cast Master Ambarish Kenghe noted that the company expects the “cast” button -- a rectangle with four “transmission waves” in the lower right corner -- to begin appearing on apps and sites. A Google Cast Developers site offers more information on the SDK, integration into apps and user experience guidelines.

Fourteen Apps

Currently, Google notes that 14 apps are Chromecast-compatible. All are streaming apps of some sort, including those from Netflix, HBO Go, Hulu Plus, or Google Play Music, in addition to an app for “inspirational programming” from Red Bull and a media organizer called Plex.

The availability of the cast button on apps and Web sites means that any screen with a HDMI port will be able to display larger images than users currently see on their devices or laptops without a monitor setup.

If it catches on with developers, there are a number of other possibilities as well. Two-screen interaction has, to this point, largely meant using a smartphone, tablet or laptop in some fashion to follow TV programming, sometimes synched through a sound track or other guideposts. Now, two-screen interaction might be driven the other way, with the smartphone, tablet or laptop becoming the primary deliverer of content, complemented by the big screen-displayed content.

Flood of New Apps?

Many Google watchers expect that this new SDK and open API will result in a flood of apps for Chromecast, possibly establishing it as a new kind of platform. One reason that expectations are high is that many apps will not have to be developed for the device. Rather, existing apps can continue to live on the laptop or mobile device and, by adding support for the API and a cast button, can now be streamed to the TV.

Many Chromecast apps will likely offer some form of micro-channel for displaying streaming content, such as the Vevo app for Chromecast that is oriented toward playing music videos. But those channels will now have the interactive capabilities of the device where they originate, not the least of which is a much more powerful searching function.